TWELVE-STRAND ROPE EMPLOYING JACKETED SUB-ROPES

1 . A method of forming a rope structure comprising the steps of:

forming a sub-rope structure comprising a core and a jacket;

twisting the sub-rope structure to form a twisted sub-rope structure;

forming the rope structure by braiding together a plurality of lengths of the twisted sub-rope structure.

2 . A method as recited in claim 1 , further comprising the steps of:

forming strands from filaments; and

combining lengths of the strands to form the core and the jacket of the sub-rope structure.

3 . A method as recited in claim 2 , in which:

the step of combining the strands to form the core comprises the step of braiding together twelve lengths of the strands; and

the step of combining the strands to form the jacket comprises the step of braiding together twelve lengths of the strands around the core.

4 . A method as recited in claim 1 , in which the step of twisting the sub-rope structure to form the twisted sub-rope structure further comprises the steps of:

determining an amount of braid twist applied when the lengths of twisted sub-rope structures are braided together to form the rope structure; and

applying sufficient pre-twist when forming the twisted sub-rope structure to compensate for the braid twist.

5 . A method as recited in claim 1 , further comprising the step of arranging a filter member between the core and the jacket.

6 . A method as recited in claim 1 , in which the step of forming the rope structure comprises the step of braiding together twelve of lengths of the twisted sub-rope structure.

7 . A rope structure comprising a plurality of lengths of a sub-rope structure comprising a core and a jacket, where a reference line substantially parallel to a longitudinal axis of the sub-rope structure when the rope sub-structure is initially formed is substantially parallel to the longitudinal axis of the rope sub-structure when the plurality of lengths of the sub-rope structure are braided together to form the rope structure.

8 . A rope structure as recited in claim 7 , in which:

lengths of strands are braided together to form the core and the jacket of the sub-rope structure; and

the strands comprise filaments.

9 . A rope structure as recited in claim 8 , in which:

the core of the rope sub-structure comprises twelve lengths of the strands; and

the jacket of the rope sub-structure comprises twelve lengths of the strands.

10 . A rope structure as recited in claim 8 , further comprising a filter member between the core and the jacket.

11 . A rope structure as recited in claim 8 , in which the rope structure comprises twelve of lengths of the sub-rope structure.

12 . A method of forming a rope structure comprising the steps of:

providing a rope sub-structure comprising a core and a jacket;

determining an amount of braid twist obtained when braiding the rope sub-structure to form the rope structure; and

forming a twisted sub-rope structure by pre-twisting the sub-rope structure to compensate for the braid twist;

braiding lengths of the twisted sub-rope structure together to form the rope structure.

13 . A method as recited in claim 12 , further comprising the steps of:

forming strands from filaments; and

combining lengths of the strands to form the core and the jacket of the sub-rope structure.

14 . A method as recited in claim 13 , in which:

the step of combining the strands to form the core comprises the step of braiding together twelve lengths of the strands; and

the step of combining the strands to form the jacket comprises the step of braiding together twelve lengths of the strands around the core.

15 . A method as recited in claim 13 , further comprising the step of arranging a filter member between the core and the jacket.

16 . A method as recited in claim 13 , in which the step of forming the rope structure comprises the step of braiding together twelve of lengths of the twisted sub-rope structure.